1. Field of the Invention
The present invention relates generally to tilt mechanisms for operating retractable coverings for architectural openings and more particularly to a counterbalanced system to facilitate the ease of operation.
2. Description of the Relevant Art
This invention relates generally to mechanisms for tilting the slats or vanes of a covering for an architectural opening, and more specifically to a counterbalanced mechanism for low effort tilting of the slats of a horizontal blind covering.
Conventional Venetian-style blinds typically comprise a fixed head rail that is mounted to a window frame or other architectural openings through mounting brackets located at the ends of the head rail. To tilt the horizontal slats of the conventional style Venetian blind, a wand hanging from the head rail is rotated. The wand is connected to a tilt mechanism located within the head rail. Rotation of the wand turns one or more gears of the tilt mechanism that in turn rotate a tilt rod that extends generally along the length of and is contained within the head rail.
At two or more locations along the head rail the tilt rod is operatively connected to the ends of a ladder tape. The ladder tape typically comprises two vertical cords that extend downwardly from the head rail: one in front of the slats; and one behind the slats. The lower ends of the ladder tape are typically connected to a weighted foot rail. The vertical cords of each ladder tape are connected by cross rungs that also act to cradle and support associated slats of the blind. When the tilt rod is rotated, one of the vertical cords of each ladder tape is pulled upwardly into the head rail while the other vertical cord is pulled downwardly by the weight of the foot rail as additional cord is fed from the head rail. Accordingly, the cross rungs are pivoted between horizontal and generally vertical orientations, thereby tilting the slats they are supporting.
The conventional tilt mechanism is typically limited to use in Venetian-style blinds having a stationary head rail, which can contain and support the tilt mechanism including the longitudinally extending tilt rod. Fixed head rails are generally not considered to be aesthetically pleasing. Accordingly, head rails are often covered with valances or in other situations stationary slats are adhesively secured to the head rail to give the impression that the slats of the blind assembly extend the entire length of the blind.
Although conventional tilt mechanisms are generally very effective, friction in the mechanisms can require a significant amount of effort to be expended by the user to tilt the slats. Further, to tilt the slats from one closed position all the way to the opposite closed position a significant number of turns of the tilt wand are often required (typically 6 or more). A certain level of hand dexterity is required to operate the small diameter wand (larger diameter wands would distract from the aesthetics of the blinds) and accordingly, certain persons, such as the elderly, may find the conventional tilt mechanisms difficult to operate.
A balanced mechanism for the tilting of horizontal blinds incorporating a tiltable head rail along with a blind assembly incorporating the balanced tilt mechanism are described. The balanced tilt mechanism permits the slats (or vanes) of the horizontal blinds to be pivoted in either clockwise or counterclockwise directions with minimal effort by gently lifting or pulling on a weighted tassel hanging from the end of a tilt actuator cord.